The internal-combustion engine was synonymous with the automobile throughout the 20th century. But its future is now at risk, since it faces competition from both the hybrid gasoline- and diesel-electric engine (that is, the hybrid) and from the fuel cell.1 As befits any new technology, fuel cells (see sidebar "Challenge or opportunity?") and hybrids are attracting heavy investment and media attention. You would think that the internal-combustion engine had nowhere to go but out.
The internal-combustion engine will be the dominant power plant in new cars sold until at least 2025
But today’s internal-combustion engine is far more advanced and efficient than its predecessors. Over the past 20 years, automakers have significantly improved its power, its fuel efficiency, and its emissions, with more changes to come. Not that it will always outperform the alternatives; fuel cells—rapidly gaining market acceptance and slated to be in mass production for some premium markets by 2010—may become the leading technology of the late 21st century. However, given the current economics of the internal-combustion engine, we predict that it will still be installed in 90 percent of all new vehicles sold in developed economies in 2015 and remain dominant in...